Upgrading suspension + stiffening the body need input.

[topher455]

Im not sure why you dont want urethane bushings. I dont think there any stiffer rubber body mounts availible for our cars. The urethane mounts wont squeak like a urethane suspension bushing if that is what you are worried about. I got a set for my car from prothane and all mounts including the GNX ones were included as well as washers and sleves. Only cost about $95 from summit.HTH

 

[GoldHawg]

I just seem to remember from my impala SS missing body bushings that someone had found higher durometer bushings to replace the missing ones (that 9C1s had). As for why I would want them, I was just thinking that the poly's might be too rough; there is a reason the factory doesn't use them, yes? I thought a higher durometer option might be a nice upgrade. but if they're not available I'll probably go w/the polys.

 

[corymc]

I just seem to remember from my impala SS missing body bushings that someone had found higher durometer bushings to replace the missing ones (that 9C1s had). As for why I would want them, I was just thinking that the poly's might be too rough; there is a reason the factory doesn't use them, yes? I thought a higher durometer option might be a nice upgrade. but if they're not available I'll probably go w/the polys.

maybe the cost is much less useing rubber at the factory

 

[Grimster]

Anything wrong with these bushings: https://www.jegs.com/webapp/wcs/stores/servlet/productitem_10001_10002_762610_-1_534584

Getting ready to start improving the handling and ride.

 

[topher455]

Those look good to me. Almost exactly what was in my kit except mine were RED. I just had to have the eye candy As far as being rough I wouldnt think so since the body isnt designed to move on the chassis. The only job of the bushings is to absorb nominal vibrations from the chassis and not transmit them to the body. I think this was done to give the midsize luxury car feel desired in the eighties. Just my $.02 hopefully its worth that much

 

[MAP]

Hi Topher, folks,

I went from OEM rubber (at all bushing locations, btw - none were missing from the factory,) to aftermarket black PU, and strongly disliked the results. The car rode as if it had a terminal case of high-frequency jigglies going over even the smallest of road irregularities.

I've since gone back to the OEM rubber, but replaced #1 with a stiff plastic. This gave a nice balance between good NVH, and the subjective tightness that I was looking for.

Best,
MAP

 

[topher455]

Do you have a GNX? To my knowledge that is the only Regal to recieve all the body bushings from the factory. Or do you mean all except the ones at the rear spring perches. I enjoy the results of my urethane mounts but to each his own. That is why all cars are modded differently. I also really like the rigidity they add to the frame since the G-body frames are so soft and flexible esp. in the rear. Remove the last 2 body mount bolts on either side of the rear frame section and pull down on it. Make sure you have clean drawers handy. That is why I have modded my frame with crossmembers support braces and boxing plates and the reason I run urethane bushings. :biggrin:

 

[MAP]

Hi Topher,

No, it's a 1978 Malibu. But I've owned a whole slew of A/G bodies over the years, and have modified them all, and can therefore say from direct experience, in addition to theoretical knowledge, that they are sufficiently similar so that the claim I'm making is valid for all of them.

The subjective reaction to NVH, on the other hand, is notoriously subjective. I believe I'm more sensitive than most car enthusiasts to high-Q resonances transmitted to the cabin.

If you remove the NVH factor, then making the chassis stiffer is more straightforwardly the way to go for better handling and track performance. PU does that to a great extent, although the Delrin I used for the #1 bushing is stiffer by at least a factor of ten compared to the typical body-bushing PU durometers.

I think PU's biggest problem from an NVH standpoint is its low loss factor, which is typically only about 5%, in contrast with the 80% or so for factory OEM rubber.

Thanks,
MAP

 

[Gary Wells]

Hi Topher, folks,

I went from OEM rubber (at all bushing locations, btw - none were missing from the factory,) to aftermarket black PU, and strongly disliked the results. The car rode as if it had a terminal case of high-frequency jigglies going over even the smallest of road irregularities.

I've since gone back to the OEM rubber, but replaced #1 with a stiff plastic. This gave a nice balance between good NVH, and the subjective tightness that I was looking for.

Best,
MAP

Not to disagree, but I have been led to believe that all '86-'87 turboBuicks excepting the GNX were built without using the #'s 3 & 4 lower body bushings. I have heard that the build sheet just did not call for them. Are you the origianl owner of the car? And if not, how many owners has the car had previously? I have owned 5 of these cars and every one was missing the #'s 3 & 4 lower body bushings, and 2 of those cars I bought from the original owners.

 

[MAP]

Greetings Wells,

You're quite right (I suspect our posts crossed; see my last post.) The claim about which I have a high level of confidence as applying more-or-less uniformly across the whole A/G body spectrum, is how the chassis responds to a conversion to PU body bushings, and then how it responds to OEM rubber at all locations except #1, where I used Delrin.

But again, the perception of NVH is highly subjective and absolutely key in determining which solution paths the owner may or may not find acceptable.

It's also useful to point-out that as the suspension and tires are made stiffer, the inherent floppiness of the OEM chassis is revealed to a most unpleasant extent IMO.

Thanks,
MAP

 

[charlief1]

If you want to make the stock rubber bushins stiffer you can "bake" them. About an hour in an oven at roughly 200 degrees. Do this with good ventelation because it stinke. The drawback is that your bushings will last less time but the durometer reading will be between stock rubber and poly bushings. You can also box the section from the front to the rear and stiffen the car quite a bit.

 

[topher455]

I agree that nvh is totally subjective. I am a Chrysler Jeep Dodge tech in Florida and I see evidence of that every day. You wouldnt believe the things our customers complain about. Then again you wouldnt believe the things they dont complain about. I am slightly surprised that you went to the trouble to reinstall all new rubber bushings on the chassis then installed a rigid delrin bushing in one location. I would think this would undo the effective advantage of the rubber bushings ability to absorb nvh frequencies. I have used a sirometer on my frame twice to test nvh frequencies and there are surprisingly few present and the amplitude is quite low. (running the car in the air on jackstands of course) So my hypothesis is that most nvh on our cars is due to road irregularities and tire contact noise. I must admit I am enjoying this thread. There are alot of very intelligent people on this site and I enjoy conversing with those that, like myself, put waaaay too much thought into things.